The alien limb phenomenon is a phenomenon in which patients experience involuntary movements in a limb, which is accompanied by a feeling that the limb does not belong to them. There is some evidence to support the notion that alien limb is at least partially related to damage to areas of the parietal cortex.

Source:

Graff-Radford, J., Rubin, M.N., Jones, D.T. et al. J Neurol (2013) 260: 1880. doi:10.1007/s00415-013-6898-y